Flame arresters

Abstract

A flame arrester (FA1) having an inlet (12) and an outlet (32), a housing (13, 23, 33) between the inlet (12) and outlet (32), one or more baffle plates (14, 34) and a flame arrester element (20) located within the housing (13, 23, 33). The inlet (12) has a maximum diametric dimension (D12). A first baffle plate (14) is located downstream of the inlet (12) and the flame arrester element (20) is located downstream of the first baffle plate (14). A second baffle plate (34) is located downstream of the flame arrester element (20) and upstream of the outlet (32). The baffle plates (14, 34) are secured to the inner wall of the housing (13, 23, 33) and each has an aperture (15, 35). The aperture (15) of the first baffle plate (14) has a minimum diametric dimension of at least 0.75D12.

The invention claimed is: 
     
       1. A flame arrester comprising an inlet and an outlet, a housing between the inlet and outlet and a baffle plate and a flame arrester element located within the housing, the inlet and the outlet being on the same axis, wherein the baffle plate is attached to an internal wall of the housing and is spaced from and located between the inlet and the flame arrester element, the baffle plate comprising an aperture and where at least a portion of the baffle plate flares radially outwardly from the aperture and from an axis formed along a flow direction, in a direction from the inlet towards the flame arrester element, the aperture permitting the passage of fluid therethrough. 
     
     
       2. A flame arrester according to  claim 1 , further comprising a second baffle plate having an aperture, wherein the second baffle plate flares radially inwardly in the direction to that aperture and from an axis formed along a flow direction of that aperture. 
     
     
       3. A flame arrester according to  claim 2 , wherein the first and/or second baffle plate is frusto-conical. 
     
     
       4. A flame arrester according to  claim 1 , wherein the inlet for gas to enter the housing has a maximum diametric dimension D, and the aperture has a minimum diametric dimension of at least 0.75D. 
     
     
       5. A flame arrester according to  claim 4 , wherein the minimum diametric dimension of the aperture is 0.8D or more. 
     
     
       6. A flame arrester according to  claim 4 , wherein the maximum diametric dimension of the aperture is less than 2D. 
     
     
       7. A flame arrester according to  claim 4 , wherein the aperture defines a plane, wherein the plane is parallel to or inclined to a leading face of the flame arrester element. 
     
     
       8. A flame arrester according to  claim 4 , wherein a mid-point of the plane defined by the aperture is a distance from the leading face of the flame arrester element of 0.1D to 2.0D. 
     
     
       9. A flame arrester according to  claim 5 , wherein the minimum diametric dimension of the aperture is selected from the group consisting of ≥0.85D, ≥0.9D, ≥0.95D, ≥1.0D, ≥1.05D, and ≥1.1D. 
     
     
       10. A flame arrester comprising an inlet and an outlet, a housing between the inlet and outlet and a baffle plate and a flame arrester element located within the housing, the inlet and the outlet being on the same axis, wherein the baffle plate is attached to the internal wall of the housing and is spaced from and located upstream of the flame arrester element, the baffle plate comprising an aperture and where at least a portion of the baffle plate flares inwardly or outwardly in the flow direction to or from the aperture, the aperture permitting the passage of fluid therethrough, wherein the inlet for gas to enter the housing has a maximum diametric dimension D, and the aperture has a minimum diametric dimension of at least 0.75D, wherein the maximum diametric dimension of the aperture is less than 2D and wherein the maximum diametric dimension of the aperture is selected from the group consisting of 1.9D, 1.8D, 1.7D, and 1.6D. 
     
     
       11. A flame arrester comprising an inlet and an outlet, a housing between the inlet and outlet and a baffle plate and a flame arrester element located within the housing, the inlet and the outlet being on the same axis, wherein the housing has a larger cross-sectional area than the inlet and outlet, the baffle plate is attached to the internal wall of the housing and is spaced from and located upstream of the flame arrester element, the baffle plate comprising an aperture and where at least a portion of the baffle plate flares radially inwardly or radially outwardly in the flow direction from or to the aperture and to or from an axis formed along the flow direction, the aperture permitting the passage of fluid through the baffle plate. 
     
     
       12. The flame arrester according to  claim 1 , wherein the baffle plate extends from the housing. 
     
     
       13. The flame arrester according to  claim 2 , wherein the second baffle plate is located between the flame arrester element and the outlet. 
     
     
       14. The flame arrester according to  claim 11 , wherein the baffle plate extends from the housing. 
     
     
       15. A flame arrester according to  claim 1 , further comprising a second baffle plate having an aperture, wherein the second baffle plate is flat.